KR20150135316A - Hot-melt adhesive - Google Patents

Abstract

The present invention addresses the challenge of providing hot-melt adhesives that are applicable at low temperatures and have excellent adhesion at low temperatures, and disposable products obtained using hot-melt adhesives. The hot-melt adhesive was obtained using a vinyl aromatic hydrocarbon and had a styrene content of 35-45 wt% and a diblock content of 50-90 wt% and a 25 wt% toluene solution having a viscosity at 25 캜 of 250 mPa s or less (A) containing a radical styrene block copolymer (A1) having a styrene block copolymer (A1).

Description

Hot-melt adhesive {HOT-MELT ADHESIVE}

The present invention relates to a hot-melt adhesive, more particularly to a hot-melt adhesive used in disposable applications such as paper diapers and napkins.

Adhesives containing a thermoplastic block copolymer as a main component have been used in disposable articles such as paper diapers and napkins, and in particular, hot-melt adhesives based on styrene-based block copolymer have been widely used. For example, a paper diaper is made by bonding a polyethylene film with other members (e.g., nonwoven, elastic material such as natural rubber, water-absorbent paper, etc.) using a hot-melt adhesive. The hot-melt adhesive can be applied to various members using various methods, and the hot-melt adhesive is melted by heating to obtain an appropriate viscosity, and then the molten adhesive is applied to various members, ), Linear, strip, spiral, or sheet.

At present, improvement of the feeling of the paper diaper is required, and studies have been made to improve the flexibility and feel of the paper diaper by thinning the polyethylene film or various members mentioned above, for example, nonwoven fabric. The material cost is reduced by significantly thinning various members. However, by thinning the polyethylene film, the heat resistance is deteriorated and the application of hot (more than 150 ° C) hot-melt adhesive may lead to the problem of melting of the polyethylene film or wrinkling of the polyethylene film. Thus, adhesive manufacturers are developing low temperature-adaptive hot-melt adhesives that are applicable at low temperatures (below 140 ° C).

Considering workability and environmental aspects in the application of hot-melt adhesives, manufacturers producing paper diapers and sanitary articles strongly desire to lower the viscosity of hot-melt adhesives. Hot-melt adhesives usually include a base polymer and a plasticizer, and studies have been made to lower the viscosity of the hot-melt adhesive by a method of increasing the amount of the plasticizer by reducing the amount of the base polymer. However, the production of a paper diaper using a low-viscosity hot-melt adhesive manufactured using the above method is disadvantageous in that the balance between the adhesion to the polyethylene film constituting the member of the paper diaper and the holding force (cohesive force) deteriorates and the softening point becomes excessive It may cause a problem that it is deteriorated.

Patent Document 1 discloses a hot-melt adhesive comprising a linear styrene block copolymer, a tackifier resin and a plasticizer (claim 1). The hot-melt adhesive of the document has a low viscosity and is suitable for application at low temperatures, but the adhesiveness at low temperatures is not sufficient.

Patent Documents 2 to 4 refer to a hot-melt adhesive containing a radical styrenic block copolymer (claim 1 of each patent document). However, the hot-melt adhesives of Patent Documents 2 to 4 have a high melt viscosity and are not suitable for carrying out application at a low temperature. However, they are insufficient in either of the peel strength, retention or tack at the low temperature, which is essential for the essential adhesion required in hot-melt adhesives used in disposable products.

Patent Document 1: JP 2004-137297 A

Patent Document 2: JP H5 (1993) -311138 A

Patent Document 3: JP 2006-8947 A

Patent Document 4: JP 2010-536957 W

It is an object of the present invention to provide a disposable product obtained by utilizing a hot-melt adhesive having excellent adhesiveness at a low temperature, and a hot-melt adhesive.

The present invention provides a hot-melt adhesive comprising a thermoplastic block copolymer (A) which is a copolymer of a vinyl-based aromatic hydrocarbon and a conjugated diene compound, as follows:

The thermoplastic block copolymer (A) is a 25% (by weight) toluene solution having a styrene content of 35 to 45 wt.% And a diblock content of 50 to 90 wt.% And a radical type viscosity of 25 mPa.s or less at 25 DEG C Styrene block copolymer (A1).

In one embodiment, the radical styrenic block copolymer (A1) comprises at least one selected from the group consisting of a three-branched or four-branched terpolymer.

In one embodiment, the hot-melt adhesive further comprises a tackifying resin (B) and a plasticizer (C).

In one embodiment, the hot-melt adhesive has a content of (A) of 15 to 30 parts by weight based on 100 parts by weight of the total weight of (A) to (C).

In one embodiment, the thermoplastic block copolymer (A) further comprises a linear styrene block copolymer (A2).

In one embodiment, the plasticizer (C) comprises at least one selected from the group consisting of naphthenic oil and paraffin oil.

The present invention also provides a disposable article obtained by applying any one of the above hot-melt adhesives.

The hot-melt adhesive of the present invention is applicable at low temperatures due to its low melt viscosity, excellent in adhesion at low temperatures, and excellent in balance between tack and holding force (cohesive force).

Disposable articles of the present invention are constructed by adhering a member such as a polyethylene film and a nonwoven web with a hot-melt adhesive so that each of the members is not peeled off even during the winter or even at low temperatures.

In the present invention, "thermoplastic block copolymer (A)" is a copolymer obtained by block copolymerization of a conjugated diene compound and a vinyl-type aromatic hydrocarbon, and usually includes those containing a vinyl- type aromatic hydrocarbon block and a conjugated diene compound block .

As used herein, the term "vinyl class aromatic hydrocarbon" means an aromatic hydrocarbon compound having a vinyl group, and specific examples thereof include styrene, o-methylstyrene, p-methylstyrene, p- -Dimethylstyrene,? -Methylstyrene, vinylnaphthalene, vinyl anthracene, and the like. Styrene is particularly preferred. These vinyl class aromatic hydrocarbons may be used singly or in combination.

"Conjugated diene compound" means a diolefin compound having at least one pair of conjugated double bonds. Specific examples of the "conjugated diene compound" include 1,3-butadiene, 2-methyl-1,3-butadiene (or isoprene), 2,3-dimethyl-1,3-butadiene, , 3-hexadiene. Particularly, 1,3-butadiene and 2-methyl-1,3-butadiene are preferable. These conjugated diene compounds may be used alone or in combination.

The thermoplastic block copolymer (A) according to the present invention may be a non-hydrogenated product or a hydrogenated product.

Specific examples of the "non-hydrogenated product of the thermoplastic block copolymer (A)" include those in which the block based on the conjugated diene compound is not hydrogenated. A specific example of the "hydrogenation product of thermoplastic block copolymer (A)" includes block copolymers in which the block based on the conjugated diene compound is fully or partially hydrogenated.

The hydrogenated ratio of the "hydrogenation product of the thermoplastic block copolymer (A)" may be expressed as "hydrogenation ratio ". The "hydrogenation ratio" of the " hydrogenation product of the thermoplastic block copolymer (A) "is referred to as the conversion ratio of the double bond to the saturated hydrocarbon bond by hydrogenation based on all aliphatic double bonds contained in the block based on the conjugated diene compound. The "hydrogenation ratio" can be measured with an infrared spectrophotometer, a nuclear magnetic resonance spectrometer or the like.

Specific examples of the "non-hydrogenated product of the thermoplastic block copolymer (A)" include a styrene-isoprene block copolymer (also referred to as "SIS") and a styrene-butadiene block copolymer (also referred to as "SBS"). Examples of "hydrogenated products of thermoplastic block copolymer (A)" include hydrogenated styrene-isoprene block copolymers (also referred to as "SEPS") and hydrogenated styrene-butadiene block copolymers (also referred to as "SEBS").

The thermoplastic block copolymer (A) may be used singly or in combination of plural classes.

The present invention utilizes a radical styrenic block copolymer (A1) as a family of thermoplastic block copolymers (A). The radical type styrene block copolymer is a branched styrene block copolymer having a plurality of linear styrene block copolymers as a center and a radially protruding structure from a coupling agent. Linear styrene block copolymers are linear copolymers of blocks of styrene combined with blocks of conjugated diene.

Specific examples of the radical type styrene block copolymer are shown below.

(S - E) _n Y (1)

In the formula, n is an integer of 2 or more, S is a styrene block, E is a conjugated diene compound block, and Y is a coupling agent. n is preferably 3 or 4. Polymers with n = 3 are referred to as triplet terrain, while copolymers with n = 4 are referred to as quadruplet terrain. When n is 3 or 4, the obtained hot-melt adhesive exhibits a low melt viscosity and a high holding force (cohesive force). The conjugated diene compound is preferably butadiene or isoprene.

The radical type styrene block copolymer (A1) is a resin composition in the present invention and comprises a styrene-conjugated diene block copolymer represented by the following formula at a ratio of:

S - E (2)

Wherein S and E have the same meanings as defined above. The styrene-conjugated diene block copolymer of formula (2) may sometimes be referred to as "diblock ".

Coupling agents are multifunctional compounds that radically bind linear styrene block copolymers. There is no particular limitation on the type of coupling agent.

Examples of coupling agents are silane compounds such as halogenated silanes or alkoxysilanes, tin compounds such as tin halides, epoxy compounds such as polycarboxylate esters or epoxidized soybean oil, acrylic esters such as pentaerythritol tetraacrylate, divinyl compounds Such as epoxy silane or divinyl benzene, and the like. Specific examples thereof include trichlorosilane, tribromosilane, tetrachlorosilane, tetrabromosilane, methyltrimethoxysilane, ethyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, tetramethoxysilane, tetra Ethoxy silane, tetrachlorotin, diethyl adipate, and the like.

In the present invention, the radical type styrene block copolymer (A1) has a styrene content of 35 to 45% by weight, a diblock content of 50 to 90% by weight and a 25% (by weight) 250 mPa s or less.

The "styrene content" is the ratio of the styrene block contained in (A1). The styrene content is 35 to 45 wt%, more preferably 35 to 40 wt%.

(A1) is within the above range, whereby the hot-melt adhesive of the present invention is excellent in the balance between the holding force (cohesive force), tack and adhesive property at low temperature.

The "diblock content" is the ratio of the styrene-conjugated diene compound block copolymer of formula (2) contained in (A1). The diblock content is 50 to 90 wt%, more preferably 55 to 85 wt%.

(A1) is within the above-mentioned range, whereby the hot-melt adhesive of the present invention is excellent in tackiness at low temperatures. Due to the excess content of the branched structural component represented by the formula (1), the diblock content of (Al) of less than 50% by weight can sometimes lead to poor adhesion or deterioration of the tack of the obtained hot-melt adhesive . The diblock content of (A1) in excess of 90% by weight can make it difficult to improve the holding power of the hot-melt adhesive even when it has a radical structure.

"Viscosity at 25 ° C as a 25% (by weight) toluene solution" refers to a viscosity at 25 ° C as a solution having a concentration of 25% by weight with toluene as a solvent and is measured with various viscometers such as Brookfield BM- Can be measured using a viscometer (spindle number 27).

(25% by weight) toluene solution of (A1) has a viscosity of 250 mPa 占 퐏 or less and a viscosity of 100 to 250 mPa 占 퐏 at 25 占 폚. In particular, the viscosity is more preferably 130 to 200 mPa · s.

In the hot-melt adhesive of the present invention, "25% (by weight) toluene solution of (A1) within this range viscosity at 25 ° C" leads to a significant reduction in melt viscosity, have.

HJ10, HJ12, HJ13, and HJ15 are commercially available from Asahi Kasei Chemicals Corporation as a radical styrenic block copolymer (A1).

In the present invention, the thermoplastic block copolymer (A) comprises a styrene block copolymer different from (A1), and preferably includes a linear styrene block copolymer (A2). The inclusion of (A1) as well as (A2) can enable further improvement in balance between tack, holding power (cohesion) and adhesion at low temperatures.

In this specification, the word "linear" refers to a linear structure. The linear styrene block copolymer refers to a styrene block copolymer having a linear structure.

Commercially available products can be used as linear styrene block copolymers. Examples include Asaprene T439 (trade name), Asaprene T436 (trade name) and Asaprene T432 (trade name) (manufactured by Asahi Kasei Chemicals Corporation); TR2600 (trade name) (manufactured by JSR Corporation); Stereon 857 (trade name) and Stereon 841A (trade name) (manufacturer Firestone Corporation); Kraton D1118 (trade name) (manufactured by Kraton Polymers, Inc.); Sol T166 (trade name) (manufacturer Enichem, Ltd.); Quintac 3433N (trademark) and Quintac 3421 (trade name) (manufacturer Zeon Corporation). Commercially available products of the thermoplastic block copolymer (A) may be used alone or in combination.

The thermoplastic block copolymer (A) optionally comprises other styrene block copolymer (A3) not belonging to (A1) or (A2).

Examples of other styrene block copolymers (A3) are TR2500 (trade name) (manufactured by JSR Corporation); Quintac 3450 (trade name) and Quintac 3460 (trade name) (manufacturer Zeon Corporation); Sol T6414 (trade name) (manufacturer Enichem, Ltd).

The hot-melt adhesive of the present invention comprises a tackifier resin (B) and a plasticizer (C). The tackifying resin is not particularly limited as long as it is conveniently used in a hot-melt adhesive and it is possible to provide the intended hot-melt adhesive of the present invention.

Examples of the tackifier resin (B) include natural rosin, modified rosin, hydrogenated rosin, glycerol ester of natural rosin, glycerol ester of modified rosin, pentaerythritol ester of natural rosin, pentaerythritol ester of modified rosin, Hydrogenated derivatives of hydrogenated terpene, hydrogenated derivatives of terpene terpenes, polyterpene resins, phenol class hydrogenated derivatives of modified terpene resins, aliphatic petroleum hydrocarbon resins, aliphatic petroleum hydrocarbon resins, aliphatic petroleum hydrocarbon resins, Hydrogenated derivatives of petroleum hydrocarbon resins, aromatic petroleum hydrocarbon resins, hydrogenated derivatives of aromatic petroleum hydrocarbon resins, cyclic aliphatic petroleum hydrocarbon resins, and hydrogenated derivatives of cyclic aliphatic petroleum hydrocarbon resins. These tackifying resins may be used alone or in combination. Further, a liquid tackifier resin can be used as the tackifier resin having a colorless to pale yellow tint and substantially free of smell and having satisfactory thermal stability. When the performance is considered from a comprehensive viewpoint, a hydrogenated derivative such as a resin is preferable as a tackifier resin. The non-hydrosalative tackifying resins are optionally utilized in combination.

A commercially available product can be used as the tackifier resin (B). Examples of commercially available products include ECR179EX (trade name) (manufactured by Tonex Co., Ltd.); Maruka Clear H (trade name) (manufactured by Maruzen Petrochemical CO., LTD.); Alcon M100 (trade name) (manufactured by Arakawa Chemical Industries, Ltd.); I-MARV S100 (trade name) (manufactured by IDEMITSU KOSAN CO., LTD.); Clearon K100 (trade name), Clearon K4090 (trade name) and Clearon K4100 (manufactured by YASUHARA CHEMICAL CO., LTD.); ECR179EX (trade name) and ECR231C (trade name) (manufactured by Tonex Co., Ltd.); Regalite C6100L (trade name) and Regalite C8010 (trade name) (manufactured by Eastman Chemical Company); And FTR2140 (trade name) (manufacturer Mitsui Chemicals, Inc.). Examples of non-hydrosalative tackifying resins include Quinton DX390N (trade name) and Quinton DX395 (trade name) (manufacturer Zeon Corporation). These commercially available tackifying resins may be used alone or in combination.

The plasticizer (C) is blended for the purpose of reducing the melt viscosity of the hot-melt adhesive, thereby imparting flexibility to the hot-melt adhesive and improving the wettability of the hot-melt adhesive to the adherend. There is no particular limitation so long as the plasticizer is compatible with the block copolymer and the desired hot-melt adhesive of the present invention can be obtained. Examples of the plasticizer (C) include paraffin oil, naphthenic oil and aromatic oil. Colorless and odorless naphthenic oils are particularly preferred.

A commercially available product may be used as the plasticizer (C). Examples thereof include White Oil Broom 350 (trade name) (manufactured by Kukdong Oil & Chemicals Co., Ltd.); Diana Fresia S32 (trade name), Diana Process Oil PW-90 (trade name) and DN Oil KP-68 (trade name) (manufacturer IDEMITSU KOSAN CO., LTD.); Enerper M1930 (trade name) (manufacturer BP Chemicals, Inc.); Register (trade name) (manufactured by Crompton Corporation); Primol 352 (trade name) (manufacturer ESSO Corp.); Process Oil NS100 (Manufacturer IDEMITSU KOSAN CO., LTD.); And KN4010 (trade name) (manufacturer PetroChina Company Limited). These plasticizers (C) may be used alone or in combination.

In the hot-melt adhesive of the present invention, the content of (A) is 3 to 60 parts by weight, preferably 8 to 45 parts by weight, more preferably 15 to 15 parts by weight, based on 100 parts by weight of the total weight of (A) To 35 parts by weight, particularly preferably 10 to 30 parts by weight. The content of (A) within the above range makes the hot-melt adhesive superior in adhesiveness, tack and holding force at low temperatures, and can be applied at low temperatures.

If desired, the hot-melt adhesive according to the invention optionally further comprises various additives. Examples of the various additives include a stabilizer and a particulate filler.

The "stabilizer" is blended in order to prevent the decrease of the molecular weight of the hot-melt adhesive by heat, the occurrence of gelation, the coloring, the smell and the like thereby improving the stability of the hot-melt adhesive, There is no particular limitation. Examples of "stabilizers" include antioxidants and ultraviolet absorbers.

"Ultraviolet absorber" is used to improve the light resistance of a hot-melt adhesive. "Antioxidant" is used to prevent oxidative degradation of the hot-melt adhesive. There are no particular restrictions on antioxidants and ultraviolet absorbers as long as they are normally used in disposable articles and the intended disposable article mentioned below can be obtained.

Examples of antioxidants include phenol antioxidants, sulfur antioxidants and phosphorus antioxidants. Examples of ultraviolet absorbers include benzotriazole ultraviolet absorbers and benzophenone ultraviolet absorbers. In addition, a lactone stabilizer may be added. These additives may be used alone or in combination.

Commercially available products can be used as stabilizers. Examples include SUMILIZER GM TM, SUMILIZER TPD TM and SUMILIZER TPS TM (manufactured by Sumitomo Chemical Co. Ltd.); IRGANOX 1010 TM, IRGANOX HP2225FF TM, IRGAFOS 168 TM and IRGANOX 1520 TM (manufacturer Ciba Specialty Chemicals Inc.); And JF77 (trade name) (manufactured by Johoku Chemical Co., Ltd). These stabilizers may be used alone or in combination.

The hot-melt adhesive of the present invention is produced by blending the components in a predetermined ratio, optionally blending various additives, melting the mixture by heating, and then mixing. Specifically, the hot-melt adhesive is prepared by filling the components in a melt-mixing vessel equipped with an agitator, and then mixing the components under heating.

The obtained hot-melt adhesive preferably has a melt viscosity at 120 ° C of 10,000 mPa · s or less, a melt viscosity at 140 ° C of 5,000 mPa · s or less, and a softening point of 75 ° C or more. "Melt viscosity" refers to the melt viscosity of the hot-melt adhesive and is measured with a Brookfield RVT-type viscometer (spindle number 27). The "softening point" is referred to as the temperature at which the hot-melt adhesive softens and begins to deform upon heating of the material. Ring and Ball method (method specified by Japan Adhesive Industry Association Standard JAI-7-1999).

The hot-melt adhesive according to the present invention has a melt viscosity at 120 占 폚 of 10,000 mPa 占 퐏 or less, a viscosity at 140 占 폚 of 5,000 mPa 占 퐏 or less, and therefore is applicable at a low temperature (140 占 폚 or less). Further, when the softening point is 75 캜 or higher, the hot-melt adhesive may be supplied in a liquid or semi-liquid form. It is preferable from the environmental point of view that the hot-melt adhesive can be stored in a temperature-holding container in a liquid or semi-liquid form and can be supplied by itself. That is, in the production of the hot-melt adhesive, the generation of the waste material can be lowered and the power consumption can be reduced.

The hot-melt adhesive according to the present invention preferably has a holding force of at least 10 minutes, more preferably at least 30 minutes, particularly preferably at least 50 minutes at 40 DEG C in the holding force evaluation method mentioned in the embodiment.

The hot-melt adhesive according to the present invention preferably has a peel strength (10 DEG C, 20 DEG C) of 1,000 gf / inch (8.8 N / 2.54 cm) or more when measured by the peeling strength evaluation method mentioned in Examples, Is 2,000 gf / inch (9.8 N / 2.54 cm).

The hot-melt adhesive according to the present invention preferably has a loop tack of 1,000 gf / inch (9.8 N / 2.54 cm) or more, more preferably 1,500 gf / inch (14.7 N / 2.54 cm), particularly preferably 2,000 gf / inch (19.6 N / 2.54 cm) or more.

The hot-melt adhesive according to the present invention is widely used in paper processing, bookbinding, disposable products, and the like, and is mainly used in disposable products. There is no particular restriction on a "disposable article" if it is a so-called sanitary material. Examples include paper diapers, sanitary napkins, pet sheets, hospital gowns, surgical white garments, and the like.

The present invention in another aspect provides a disposable article obtained by the non-contact coating of the hot-melt adhesive at low temperature (140 캜 or less). The disposable article is constituted by combining at least one member selected from the group consisting of cloth, nonwoven fabric, rubber, resin and paper with a polyolefin film using a hot-melt adhesive according to the present invention. For reasons of durability, cost, etc., the polyolefin film is preferably a polyethylene film.

In a manufacturing line for a disposable article, the hot-melt adhesive is typically applied to one or more of various members of a disposable article (e.g., a nonwoven, etc.) and a polyolefin film, after which the film is contact- . In the case of application, a hot-melt adhesive can be ejected from various ejectors. In the present invention, the "noncontact coating" method is referred to as a coating method in which, when the hot-melt adhesive is applied, the ejector is not in contact with the member or the film. Specific examples of the noncontact coating method include a spiral coating method which can be spirally coated, an omega coating or a control seam coating method which can be coated in a wave form, a slot spray coating or a curtain spray coating method which can be coated in a flat shape, And the like.

Example

The present invention will now be described by way of examples and comparative examples for the purpose of describing in more detail and in a specific manner. They are illustrative of the invention and are not to be construed as limitations.

In the examples, unless specified otherwise, parts by weight and percentages by weight are based on where the solvent is not considered.

The components used in this embodiment are shown below.

(A) a thermoplastic block copolymer

≪ (A1) Radical type styrene block copolymer >

(A1-1) A 3-branched styrene-butadiene block copolymer having a styrene content of 39% by weight, a diblock content of 80% by weight, a 25% (by weight) toluene solution having a viscosity at 25 ° C of 165 mPa.s, HJ13 Asahi Kasei Chemicals Corporation))

(A1-2) 3-branched styrene-butadiene block copolymer (styrene content: 38% by weight, diblock content: 80% by weight, 25% by weight): toluene solution, viscosity at 25 ° C: 184 mPa.s, HJ12 Asahi Kasei Chemicals Corporation))

(A1-3) A 4-branch type styrene-butadiene block copolymer having a styrene content of 38% by weight, a diblock content of 80% by weight, a 25% by weight toluene solution having a viscosity of 155 mPa.s at 25 DEG C, HJ15 Asahi Kasei Chemicals Corporation))

(A1-4) 3-branched styrene-butadiene block copolymer (styrene content: 38% by weight, triblock content: 60% by weight, 25% by weight) Toluene solution: viscosity at 25 ° C: 177 mPa.s, HJ10 Asahi Kasei Chemicals Corporation))

≪ (A2) Linear Styrene Block Copolymer >

(A2-1) A linear styrene-butadiene block copolymer (styrene content 30 wt%, diblock content 50 wt%, 25 wt%) as a toluene solution, viscosity at 25 캜 3,100 mPa,, Asaprene T432 (manufactured by Asahi Kasei Chemicals Corporation)

(A2-2) A linear styrene-isoprene block copolymer (styrene content 43 wt%, diblock content 60 wt%, 25 wt%) as a toluene solution, viscosity at 25 캜 of 170 mPa,, Asaprene T439 Kasei Chemicals Corporation)

(A2-3) A linear styrene-isoprene block copolymer (having a styrene content of 16% by weight, a diblock content of 56% by weight, a 25% by weight toluene solution, viscosity at 25 DEG C of 810 mPa.s, Quintac 3433N Corporation))

≪ (A3) Other styrene block copolymer >

(A3-1) 3-branch type styrene-butadiene block copolymer (having a styrene content of 35% by weight, a diblock content of 40% by weight, a 25% by weight toluene solution, viscosity at 25 캜 of 490 mPa,, JSR TR2500 Manufacturer JSR Corporation))

(A3-2) A 4-branch type styrene-butadiene block copolymer having a styrene content of 40% by weight, a diblock content of 20% by weight, a 25% by weight toluene solution having a viscosity of 400 mPa.s at 25 DEG C, Sol T6414 Manufacturer Enichem, Ltd.))

(A3-3) 14.2 Branched styrene-butadiene block copolymer having a styrene content of 30% by weight, a diblock content of 50% by weight, a 25% by weight toluene solution, viscosity at 25 캜 of 600 mPa 揃 s, Soloprene 9618 Manufacturer Dynasol Inc.))

(A3-4) 3-branched styrene-isoprene block copolymer having a styrene content of 25% by weight, a diblock content of 40% by weight, a 25% by weight toluene solution, viscosity at 25 DEG C of 380 mPa.s, Quintack 3460 Manufacturer Zeon Corporation))

(A3-5) 3-branched styrene-isoprene block copolymer (styrene content 19% by weight, triblock content 30% by weight, 25% by weight toluene solution, viscosity at 25 DEG C of 550 mPa.s, Quintack 3450 Manufacturer Zeon Corporation))

(B) Tackifier resin

(B1) Hydrogenated tackifier resin (ECR179EX (Exxon Mobil Corporation))

(B2) Hydrogenated tackifier resin (Alcon M100 (manufactured by Arakawa Chemical Industries, Ltd.)

(B3) Hydrogenated tackifier resin (I-MARV S100N (manufactured by IDEMITSU KOSAN CO., LTD.))

(B4) hydrogenated tackifier resin (Regalite C6100L (manufactured by Eastman Chemical Company)

(B5) non-hydrogenated tackifier resin (Quinton DX390N (Zeon Corporation))

(B6) liquid tackifier resin (Maruka Clear H (Maruzen Petrochemical CO. LTD.))

(B7) hydrogenated tackifier resin (Plastolyn 240 (manufactured by Eastman Chemical Company)

(C) a plasticizer

(C1) paraffin oil (Diana Fresis S-32 (manufactured by IDEMITSU KOSAN CO., LTD.))

(C2) paraffin oil (Daphne Oil KP68 (manufactured by IDEMITSU KOSAN CO., LTD.))

(C3) naphthenic oil (Process Oil NS100 (manufactured by IDEMITSU KOSAN CO., LTD.))

(C4) naphthenic oil (KN4010 (manufactured by PetroChina Company Limited.))

(D) Wax

(D1) Maleic anhydride modified polypropylene wax (Rikosen TP MA6252 (Clariant (Japan) K.K.))

(E) Antioxidant

(E1) phenol antioxidant (SUMILIZER GM (manufactured by Sumitomo Chemical Co., Ltd.))

(E2) sulfur antioxidant (SUMILIZER TPD (manufactured by Sumitomo Chemical Co., Ltd.))

(E3) benzotriazole antioxidant (JF77 (manufactured by Johoku Chemical Co., Ltd.))

Preparation of hot-melt adhesives of Examples 1 to 7 and Comparative Examples 1 to 6

Each component was blended according to the formulations shown in Tables 1 to 4 and then melt-mixed at about 150 캜 to prepare a hot-melt adhesive. In Table 1 to 4, "St" refers to the styrene content, "diblock" refers to the diblock content, and "TV" refers to the 25% (by weight) toluene solution at 25 ° C.

The melt viscosity, softening point, peel strength, holding power and loop tack properties of the thus obtained hot-melt adhesive of the examples and comparative examples were tested. The results are shown in Tables 5 and 6. The properties were tested by the following methods.

[Melt viscosity]

After melting the hot-melt adhesive by heating at 120 캜 and 140 캜, the melt viscosity was measured using a Brookfield RVT type viscometer (spindle No. 27). The evaluation criteria are as follows.

[Softening point]

The softening point of the hot-melt adhesive was measured by the Ring & Ball method (the method specified by Japan Adhesive Industry Association Standard JAI-7-1999).

[Peel strength]

A hot-melt adhesive was applied to a 50 μm thick PET film with a thickness of 50 μm. The coated PET film was formed into a 2.5 cm wide strip to obtain a specimen. Each specimen was placed on a 100 μm thick polyethylene film at 20 ° C and allowed to stand at 20 ° C for 1 day. Then, the peeling was carried out at a tensile speed of 300 mm / min at 10 캜 and 20 캜, and the peel strength was measured.

[retention]

A hot-melt adhesive was applied to a 50 μm thick PET film with a thickness of 50 μm. Specimens were obtained by forming the coated PET film to a size measured by a width of 2.5 cm. A 100 μm thick polyethylene film was applied to the specimen at 20 ° C so that the contact area would be 1.0 cm x 2.5 cm. A weight of 1 kg was placed on the polyethylene film in a direction perpendicular to the contact surface, and the film was placed under the condition of 40 占 폚. The time taken before the additional drop of 1 kg was measured and taken as the holding force.

[Loop]

A hot-melt adhesive was applied to a 50 μm thick PET film with a thickness of 50 μm. The coated PET film was formed into a size measuring 2.5 cm x 10 cm to obtain a specimen. Each specimen was looped around so that the adhesive side (the surface coated with the adhesive) looked outward, and the loops were then contacted with the PE sheet at a rate of 300 mm / min at 20 ° C. Thereafter, the specimen was peeled from the PE sheet at a rate of 300 mm / min to measure the peel strength at the time of peeling, which was regarded as an initial loop tack. The specimens were stored at 20 캜 for one week and then contacted with PE sheet at a rate of 300 mm / min at 20 캜. Thereafter, the specimen was peeled off from the PE sheet at a rate of 300 mm / min to measure the peel strength at the time of peeling, which was regarded as a loop tack after one week.

As shown in Tables 1 to 6, the hot-melt adhesives of Examples are excellent in melt viscosity, softening point, peel strength, holding force and loop tack because they contain component (A1). On the contrary, the hot-melt adhesives of the comparative examples are considerably poor in either of the performances in comparison with the hot-melt adhesives of the embodiments because they do not contain the component (A1).

(A1), it is proved that the hot-melt adhesive is improved in the above-mentioned performances, can be applied at a low temperature of 140 DEG C or lower in the production of the disposable article, and each member of the disposable article hardly peels in winter .

The present invention provides a disposable article obtained by applying a hot-melt adhesive and a hot-melt adhesive. The hot-melt adhesives according to the invention are particularly suitable for the production of disposable articles.

Claims (4)

A hot-melt adhesive composed of a thermoplastic block copolymer (A) which is a copolymer of a vinyl-based aromatic hydrocarbon and a conjugated diene compound, such as:
The thermoplastic block copolymer (A) is a 25% (by weight) toluene solution having a styrene content of 35 to 45 wt.% And a diblock content of 50 to 90 wt.% And a radical type viscosity at 25 DEG C of 250 mPa.s or less Styrene block copolymer (A1). The hot-melt adhesive according to claim 1, wherein the radical styrenic block copolymer (A1) comprises at least one member selected from the group consisting of a three-branched type or a four-branched type. 3. The hot-melt adhesive according to claim 1 or 2, wherein the thermoplastic block copolymer (A) further comprises a linear styrene block copolymer (A2). A disposable article obtained by applying a hot-melt adhesive according to any one of claims 1 to 3.